Field of the Invention
The present invention relates to a hydroxylated-fullerene-containing solution containing at least one of a hydroxylated fullerene and a hydroxylated fullerene derivative (hereinafter, at least one of a hydroxylated fullerene and a hydroxylated fullerene derivative is referred to as a “hydroxylated fullerene”). The invention also relates to a resin molding and a resin composition in each using the hydroxylated-fullerene-containing solution, and a method for producing each of the resin molding and the resin composition.
Description of the Related Art
In recent years, many researches have been made about nanocomposites each composed of a synthetic resin materials and a nanomaterials such as fullerene, carbon nanotubes, or a graphene. For example, the following have been performed: mixing a fullerene, which is a nanomaterial, with a resin solution; melting, kneading and mixing a fullerene with a resin solution; and adding/mixing a fullerene in polymerization.
In order to exhibit functions of a fullerene, which is a nanomaterial, to a maximum degree, it is necessary to disperse the fullerene evenly to a nano-level size (that is, nano-disperse the fullerene).
However, a hydroxylated fullerene, which is in the form of nanoparticles, has a large surface area and a small distance between the particles. Consequently, the particles aggregate remarkably easily. Thus, it is difficult to produce a stable nano-dispersed system thereof industrially. Furthermore, a solvent in which a hydroxylated fullerene is completely evenly dissolved is limited in number. It is therefore considerably difficult to economically exhibit functions (such as strength, hardness, and ultraviolet absorbing power) of the hydroxylated fullerene, which is expensive in a composite material of the hydroxylated fullerene with a resin.
JP-A-2004-75933 discloses that a resin composition is obtained by melting and kneading polyhydroxylated fullerene or polyhydroxylated fullerene hydrogenfulfate ester and a thermoplastic resin, and a resin composition is obtained by polymerizing polyhydroxylated fullerene or polyhydroxylated fullerene hydrogensulfate ester and a monomer or thermoplastic resin precursor.
JP-A-2005-97329 discloses a high-concentration fullerene derivative composition in which a fullerene derivative is dissolved in a solvent such as a formamide, sulfoxide or sulfon.
In the resin composition disclosed in JP-A-2004-75933, when melting and kneading polyhydroxylated fullerene or polyhydroxylated fullerene hydrogensulfate ester and a thermoplastic resin, or when polymerizing polyhydroxylated fullerene or polyhydroxylated fullerene hydrogensulfate ester and a monomer or thermoplastic resin precursor, a part of polyhydroxylated fullerene or polyhydroxylated fullerene hydrogensulfate ester remains easily as aggregates. In particular, since a fullerene derivative has a very high polarity such as a hydroxylated fullerene having many hydroxyl groups, a part of the hydroxylated fullerene remains as aggregates.
It is therefore impossible to economically exhibit functions (such as strength, hardness, and ultraviolet absorbing power) of the hydroxylated fullerene in the thermoplastic resin composition. When a film or resin molding is produced from such a resin composition, an aggregate is present on the surface of the film or resin molding so that various problems are caused. For example, the aggregate is peeled to cause problems, such as contamination with foreign substances, at the stage of a product of the film or resin molding. Accordingly, there is caused a problem that the film or resin molding is unusable for precise products.
As disclosed in JP-A-2005-97329, when a hydroxylated fullerene is dissolved in a solvent such as a formamide, sulfoxide or sulfone, the hydroxylated fullerene comes not to be dissolved in the solvent when the number of hydroxyl groups of the hydroxylated fullerene is 44 or more. Accordingly, a stable nano-dispersed system cannot be produced to make it impossible to economically exhibit functions (such as strength, hardness, and ultraviolet absorbing power) of the hydroxylated fullerene in thermoplastic resin composites.
Such a solvent has a boiling point of 150° C. or higher. Thus, in order to remove the solvent (liquid medium), it becomes necessary to heat and dry the solution at high temperature, so that the base resin may be unfavorably denatured. In order to avoid this inconvenience, an expensive vacuum apparatus or the like is required for drying the solution at low temperature. As a result, the resultant cannot be continuously processed in the form of a film or some other. There therefore remains a problem that remarkably high facility costs are required and the resultant products are deteriorated in productivity.